作业帮已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/06 04:54:41
xQAJ@J@IELsЅ @nfvZJI 4*Vlz6?MV^I&ik̟{y_3u;F U
^OTx*&"a5'bDUL#93dچg3~ K
ʱO-nVi[.dc[~X{;oC `) Y RbPO֊,ߗI2E N:^|zTvtȢ1#"* Y &0)PcsPO%9Gu_:pN?;JV2E~-Rʏ^
已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y
已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y
已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y
[2x/(x²-2xy+y² )]* [(x²-y²)/(x+y)]+2y/(x-y) 【电脑上录入表达式,尽可能多用括号,否则多歧义】
=[2x/(x-y)²]* [(x+y)(x-y)/(x+y)]+2y/(x-y)
=2x/(x-y)+2y/(x-y)
=2(x+y)/(x-y) 【分子分母都除以y】
=2(x/y+1)/(x/y-1)
=2(1/2+1)/(1/2-1)
=-6
问题不全？
∵ x/y=1/2
∴y=2x
∴2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/(x-y)
=2x(x+y)(x-y)/[x-y)²(x+y)+2y/(x-y)
=2x/(x-y)+2y/(x-y)
=2(x+y)/(x-y)
=6x/x
=6